This invention relates to a contact probe to be contacted, under pressure, with a given electrical part such as a liquid crystal display unit, or the like.
In testing a liquid crystal display unit or the like, one end of a contact probe is brought into contact, under pressure, with an electrode pad of the liquid crystal display unit and the other end is connected to testing equipment. Owing to this arrangement, signals can be input and output.
As shown in FIG. 1, a typical contact probe 1 has a plurality of leads 3 arranged in array on a surface of an insulating film in an intimately contacted manner. A distal end portion of each lead 3 projects from one side edge of the insulating film 2 to thereby define a contact end 7 with respect to an electronic part.
The leads 3 are formed, for example, by a plating process for growing the thickness thereof to a predetermined level. The insulating film 2 restricts contact ends 7 of the leads 3 to orderly arrange (securement of pitches) the leads 3 and at the same time enables the attainment of a degree of freedom of flexure of each contact end 7 necessary for pressure contact by flexibility of the insulating film 2.
In the contact probe 1, the insulating film 2 is adhered to a rigid block 4, and the contact end 7 of the contact probe 1 projects from an end edge of the rigid block 4, so that the contact end 7 is contacted, under pressure, with an electrode pad 6 of a liquid crystal display unit 5 due to flexibility of the insulating film 2.
However, the conventional contact probe of this type has the shortcoming in that since a plurality of leads, which are as small as about 20 .mu.m in thickness, are arranged in small pitches on a polyimide (insulating) film 2, which is as thin as about 75 .mu.m in thickness, the leads 2 are peeled off the insulating film 2 by a flexing load applied to its pressure contact end 7 when it is contacted, under pressure, with the electrode pad 6, thus jeopardizing its pressure contact with the electrode pad 6.
Moreover, since the leads 3 arranged at such small pitches are small and thin as mentioned above, sufficient elasticity of the leads 3 is difficult to obtain at the time of flexure and a sufficient pressure contact with the electrode pad 6 is difficult to expect. Therefore, improvement is demanded.
The present invention has been accomplished under the abovementioned situation.